Lubricant spray polymers

ABSTRACT

Disclosed are copolymers of alkyl methacrylate monomers wherein said alkyl methacrylate monomers comprise at least: a. Monomers (A) selected from C6-C10 alkyl methacrylate monomers, and b. Monomers (B) selected from C10-C18 alkyl methacrylate monomers, wherein the mass ratio of Monomers (B) in the copolymer to Monomers (A) in the copolymer is about 99:1 to about 60:40 by weight. In some cases, the copolymers are of lauryl methacrylate and C 8 alkyI methacrylate. Also disclosed are methods for the preparation of the copolymers.

FIELD OF INVENTION

This invention relates to a copolymer, its synthesis and methods ofusing it.

TECHNICAL BACKGROUND

The primary function of lubricants is to decrease friction. Frequently,however, lubricating oils need additional properties to be usedeffectively. For example, lubricants used in the crankcases of largediesel engines, such as, for example, marine diesel engines, are oftensubjected to operating conditions requiring special considerations.

Marine diesel engines may generally be classified as slow-speed,medium-speed, or high-speed engines, with the slow-speed variety beingused for the largest, deep shaft marine vessels and certain otherindustrial applications. Slow-speed diesel engines are unique in sizeand method of operation. The larger units may approach 200 tons inweight and be upward of 10 feet wide and 45 feet high. The output ofthese engines can be as high as 100,000 horsepower with enginerevolutions of 60 to about 200 revolutions per minute. They aretypically of crosshead design and operate on a two-stroke cycle.

In large diesel engines of the crosshead type used in marine and heavystationary applications, the piston cylinders are lubricated separatelyfrom the other engine components. The cylinders are lubricated on atotal loss basis with the cylinder oil being injected separately intoeach cylinder by means of lubricators positioned around the cylinderliner. Oil is distributed to the lubricators by means of pumps, whichare, in modern engine designs, actuated to apply the oil directly ontothe rings to reduce oil wastage.

The unique design of these engines creates the need for lubricants withenhanced rheology properties. Because slow-speed engines run at a lowertemperature than mid- or fast-speed engines, they are more prone tocorrosion. Accordingly, lubricants used in a marine engine must protectthe engine parts from corrosion, especially rust. Rust is produced whenferrous metal engine components come in contact with water, which istypically produced by the internal combustion process or from externalsources. Regardless of the source, rust and corrosion reduce engineefficiency and lifetime.

Also, the fuels commonly used in these diesel engines typically containsignificant quantities of sulfur. During the combustion process, thesulfur can combine with water to form sulfuric acid, the presence ofwhich leads to corrosive wear. In particular, in two-stroke engines forships, areas around the cylinder liners and piston rings can be corrodedand worn by the acid. Therefore, it is important for diesel engine toresist such corrosion and wear by being properly lubricated.

To prevent corrosion, the lubricant must be applied to the cylinderwall, typically by a pulse lubricating system or by spraying thelubricant onto the cylinder wall through an injector. In marine enginesthe lubricant is injected or sprayed on the cylinder liner and spreadhorizontally by the sprayer or injector and vertically by the pistonrings when the piston is in its upward motion. The lubricant is not usedin a circulating system; when the excess lubricant comes to the bottomof cylinder it is discarded. Typically fresh lubricant is injected everyfour to eight strokes depending on the engine speed.

Thus, there is a need for a lubricant additive that will provideeffective oxidation and corrosion resistance without posing theenvironmental hazards and cost of other oxidation and corrosioninhibitors. Additionally, because the lubricating oil is not circulatedin marine engines, any rheology improvements that enhance lubricatingefficacy or reduce the amount of oil used could significantly increaseengine life and decrease costs.

SUMMARY

We have found new copolymers that can modify the rheology of a marinelubricant to provide enhanced lubrication properties. In particular,marine engine lubricating oils comprising the copolymers of thedisclosure as an additive surprisingly cover marine engine pistoncylinder walls more completely than prior art oils (with or withoutadditional additives), thereby leading to better lubrication and lessengine cylinder wear and corrosion.

We have also recognized that the method in which the copolymer is madecan control the properties of the copolymer.

In a first aspect, the present disclosure provides a copolymer of alkylmethacrylate monomers wherein said alkyl methacrylate monomers compriseat least:

a. Monomers (A) selected from C6-C10 alkyl methacrylate monomers, andb. Monomers (B) selected from C10-C18 alkyl methacrylate monomers. Theratio of Monomers (B) in the copolymer to Monomers (A) in the copolymeris about 99:1 to about 10:90 by weight. In an embodiment, A is selectedfrom C6-C9 alkyl methacrylate monomers. In another embodiment, B isselected from C11-C18 alkyl methacrylate monomers. In anotherembodiment, the ratio of Monomers (B) in the copolymer to Monomers (A)in the copolymer is about 99:1 to about 60:40 by weight.

In a second aspect, the present disclosure provides a copolymer obtainedby combining at least Monomers (A) and Monomers (B) in a mixture andco-polymerizing the monomers, wherein the monomers are present in a massratio of about 99:1 to about 10:90, preferably about 99:1 to about60:40, Monomers (B) to Monomers (A), and wherein Monomers (A) andMonomers (B) are distinct from one another.

In a third aspect, the present disclosure provides a method of making acopolymer as described above.

All publications referenced herein are incorporated by reference intheir entirety to the extent they are not inconsistent with theteachings presented herein.

DETAILED DESCRIPTION

In the first aspect, the present disclosure provides a copolymer ofalkyl methacrylate monomers wherein said alkyl methacrylate monomerscomprise at least:

a. Monomers (A) selected from C6-C10 alkyl methacrylate monomers, and b.Monomers (B) selected from C10-C18 alkyl methacrylate monomers, whereinthe mass ratio of Monomers (B) in the copolymer to Monomers (A) in thecopolymer is about 99:1 to about 10:90, preferably 99:1 to 60:40, byweight.

The ratio of monomers in all aspects of the disclosure can be adjustedto manipulate the characteristics of the copolymer as desired. Forexample, the monomers can be present in ratios of Monomers (B) toMonomers (A) of 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40:60, 45:55,50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5, and99:1. In one embodiment, the monomers are present in ratios of Monomers(B) to Monomers (A) of 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10,95:5, and 99:1.

In some embodiments of all aspects of the disclosure, the Monomers (A)are linear or branched C₈alkyl. In some embodiments, Monomers (A) are2-ethylhexyl methacrylate.

In some embodiments of all aspects of the disclosure, the copolymer usedin the lubricant composition according to the invention is prepared froma mixture of monomers that comprises at least two monomers: one monomer(A) and one monomer (B), distinct from one another. The monomers arepreferably chosen from monomers which, when polymerized, form acopolymer that is soluble in liquid, preferably in oil, more preferablyin marine diesel engine oil lubricants.

In another embodiment of all aspects of the disclosure, the copolymer isa copolymer of a mixture of monomers comprising at least: a C8 alkylmethacrylate, a C12 alkyl methacrylate, a C14 alkyl methacrylate, and aC16 alkyl methacrylate, and they are present in the mixture in weightratio of:

-   -   from 5 to 30% C8 alkyl methacrylate,    -   from 40 to 70% C12 alkyl methacrylate,    -   from 12 to 35% C14 alkyl methacrylate,    -   from 1 to 12% C16 alkyl methacrylate, from 0.1 to 15%,        preferably from 0.5 to 10%, more preferably from 1 to 5% other        methacrylates, by weight with regard to the total weight of the        mixture.

In another embodiment of all aspects of the disclosure, the copolymer issubstantially free of monomers other than monomer (A) and monomer (B),particularly free of methacrylates having a C1-C5 alkyl group,including, for example, methyl methacrylate. Monomers such as methylmethacrylate decrease the solubility of the resulting copolymer in oil,and the presence of such monomers are limited or omitted in someembodiments.

In another embodiment of all aspects of the disclosure, the copolymer isfree of methacrylates other than monomer (A) and monomer (B),particularly methacrylates having a C1-C5 alkyl group, including, forexample, methyl methacrylate.

Typically, copolymers according to the disclosure have an average RootMean Square Radius of Gyration (Rg) as measured by Hydrodynamic ColumnChromotography-Multi Angle Light Scattering (HCC-MALS) from about 100 toabout 200 (nm) Rg, from about 120 to about 190 (nm), from about 130 to180, or from about 140 to about 170 (nm) Rg.

In the second aspect, the copolymer is obtained by combining at leastMonomers (B) and Monomers (A) in a mixture and co-polymerizing themonomers, wherein the monomers are present in a mass ratio of about 99:1to about 10:90 Monomers (B) to Monomers (A).

The copolymer may be synthesized by conventional methods for vinyladdition polymerization known to those skilled in the art, such as, butnot limited to, solution polymerization, precipitation polymerization,and dispersion polymerizations, including suspension polymerization andemulsion polymerization.

In some embodiments, the polymer is formed by suspension polymerization,wherein monomers that are insoluble in water or poorly soluble in waterare suspended as droplets in water. The monomer droplet suspension ismaintained by mechanical agitation and the addition of stabilizers.Surface active polymers such as cellulose ethers, poly(vinylalcohol-co-vinyl acetate), poly(vinyl pyrrolidone) and alkali metalsalts of (meth)acrylic acid containing polymers and colloidal (waterinsoluble) inorganic powders such as tricalcium phosphate,hydroxyapatite, barium sulfate, kaolin, and magnesium silicates can beused as stabilizers. In addition, small amounts of surfactants such assodium dodecylbenzene sulfonate can be used together with thestabilizer(s). Polymerization is initiated using an oil solubleinitiator. Suitable initiators include peroxides such as benzoylperoxide, peroxy esters such as tert-butylperoxy-2-ethylhexanoate, andazo compounds such as 2,2′-azobis(2-methylbutyronitrile). At thecompletion of the polymerization, solid polymer product can be separatedfrom the reaction medium by filtration and washed with water, acid,base, or solvent to remove unreacted monomer or free stabilizer.

In other embodiments the polymer is formed by emulsion polymerization,one or more monomers are dispersed in an aqueous phase andpolymerization is initiated using a water soluble initiator. Themonomers are typically water insoluble or very poorly soluble in water,and a surfactant or soap is used to stabilize the monomer droplets inthe aqueous phase. Polymerization occurs in the swollen micelles andlatex particles. Other ingredients that might be present in an emulsionpolymerization include chain transfer agents such as mercaptans (e.g.dodecyl mercaptan) to control molecular weight, electrolytes to controlpH, and small amounts of organic solvent, preferably water solubleorganic solvents, including but not limited to acetone, b-butanone,methanol, ethanol, and isopropanol, to adjust the polarity of theaqueous phase. Suitable initiators include alkali metal or ammoniumsalts of persulfate such as ammonium persulfate, water-soluble azocompounds such as 2,2′-azobis(2-aminopropane)dihydrochloride, and redoxsystems such as Fe(II) and cumene hydroperoxide, and tert-butylhydroperoxide-Fe(II)-sodium ascorbate. Suitable surfactants includeanionic surfactants such as fatty acid soaps (e.g. sodium or potassiumstearate), sulfates and sulfonates (e.g. sodium dodecyl 20 benzenesulfonate), sulfosuccinates (e.g. dioctyl sodium sulfosuccinate);non-ionic surfactants such as octylphenol ethoxylates and linear andbranched alcohol ethoxylates; cationic surfactants such as cetyltrimethyl ammonium chloride; and amphoteric surfactants. Anionicsurfactants and combinations of anionic surfactants and non-ionicsurfactants are most commonly used. Polymeric stabilizers such aspoly(vinyl alcohol-co-vinyl acetate) can also be used as surfactants.The solid polymer product free of the aqueous medium can be obtained bya number of processes including destabilization/coagulation of the finalemulsion followed by filtration, solvent precipitation of the polymerfrom latex, or spray drying of the latex.

The polymer can be isolated by conventional methods known to thoseskilled in the art, such as, but not limited to, solvent exchange,evaporation of solvent, spray drying and freeze-drying.

The characteristics of the copolymer obtained by combining at leastMonomers (A) and Monomers (B) in a mixture and co-polymerizing can bemanipulated by controlling the additional reagents added to thepolymerization mixture. These reagents include, but are not limited to,initiator systems and surfactants.

The type and amount initiator system used in the polymerization mixturecan influence the properties of the resulting copolymer. An initiatorsystem can be a single initiator compound (e.g., a persulfate salt) or amixture of two or more components (e.g., hydrogen peroxide and sodiumascorbate). In some examples, the initiator system can include anoxidant, reductant, and optionally a metal salt. The oxidant can be apersulfate, such as, for example, ammonium persulfate, or a peroxide,such as, for example, hydrogen peroxide (H₂O₂) or tert-butylhydroperoxide (TBHP). A desirable copolymer may be obtained, forexample, when the polymerization mixture includes tert-butylhydroperoxide in about 0.01 to about 0.06 mass percent of all monomersin the mixture. In other examples, the mixture may include tert-butylhydroperoxide in about 0.01 to about 0.03 mass percent of the monomersin the mixture. In some examples, the mixture further comprisestert-butyl hydroperoxide in about 0.013 mass percent of the monomers inthe mixture. Useful initiators for the copolymers of the presentdisclosure include any conventional initiator, including anyconventional redox initiator.

In some embodiments the reductant of the redox initiator system can beascorbic acid or a salt thereof. For example, the polymerization mixturecan include sodium ascorbate in about 0.04 to about 0.1 mass percent ofthe monomers in the mixture. In other examples, the sodium ascorbate maybe present in about 0.08 to about 0.1 mass percent of the monomers inthe mixture. In some embodiments, the polymerization mixture includessodium ascorbate in about 0.098 mass percent of the monomers in themixture.

The initiator system may also include a metal salt. The metal may be anysuitable transition metal, such as, for example, iron. In someembodiments, the metal salt of the initiator system can be ferroussulfate (FeSO₄). In some embodiments, the metal salt is present in thepolymerization mixture in about 0.0005 to about 0.1 mass percent of themonomers in the mixture. In some examples, the metal salt is added tothe polymerization mixture as a solution.

The copolymer may also be obtained for a polymerization mixture furtherincluding a surfactant. In some embodiments, the surfactant may containa sulfonate group. For example, the surfactant may include a dialkylsulfosuccinate, such as, for example, dioctyl sulfosuccinate sodiumsalt. In some examples, the surfactant may be Aerosol® OT.

The copolymer can be a random copolymer, block copolymer, or mixturethereof. In some embodiments, the copolymer is a substantially randomcopolymer (e.g., greater than 90, 95, 98, or 99 mass percent). In otherexamples, the copolymer is a partially a random copolymer and partiallya block copolymer. In these examples the weight percent ratio of randomcopolymer to block copolymer is generally 90:10, 80:20, 70:30, 60:40,50:50, 40:60, 30:70; 20:80 or 10:90. The copolymer may also be asubstantially block copolymer (e.g., greater than 90, 95, 98, or 99weight percent). In other examples, the copolymer can contain additionalmonomers in addition to Monomers (A) and Monomers (B) discussed. Theseadditional monomers can be present in an amount less than 10 weightpercent. In some embodiments, the additional monomers are present in anamount from about 0.5 to 10 weight percent, or about 1 to 10 weightpercent or about 1 to 5 weight percent or about 5 to 10 weight percent.In other embodiments, the additional monomers are present in an amountless than about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 or about 0.5 weightpercent. The additional monomers can include, for example, cross-linkingmonomers, acrylate, styrene, C₁-C₃alkyl methacrylate and other similarmonomers.

The copolymer may also be crosslinked. That is, the copolymer cancontain monomeric units that connect one or more of the backbone chainsof the polymer. In some examples, the copolymer contains crosslinkedmonomeric units present in up to about 5% by weight of the copolymer. Inother embodiments, the copolymer is not crosslinked, or uncrosslinked,and is substantially free of monomers that function as a crosslinkingagent. In other embodiments, the monomer mixture to make the copolymeris substantially free of crosslinking agents.

The crosslinked copolymer may be obtained when the polymerizationmixture includes a crosslinking agent. In some embodiments, thecrosslinking agent is a diacrylate or dimethacrylate crosslinking agent,such as, for example, 1,6-hexanediol dimethacrylate. In some examples,the mixture includes a crosslinking agent in up to about 0.005 masspercent of the monomers in the mixture.

Example copolymers are shown in Tables 1 and 2. For each example, Table1 shows the ratio of Monomers (B) to Monomers (A) (e.g., 2-ethylhexylmethacrylate), and the amount of acetone, the components of the redoxinitiator system and surfactant used. Table 2 shows the molecularweight, Rg and viscosity of each example copolymer.

In a third aspect, a method of making a copolymer as described above isdisclosed. The method includes the polymerization of Monomers (A) and aMonomers (B), wherein the mass ratio of Monomers (B) in the copolymer toMonomers (A) in the copolymer is about 99:1 to about 10:90 by weight(e.g., 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40:60, 45:55, 50:50,55:45, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5, 99:1).

In some embodiments, the method includes: combining Monomers (B) andMonomers (A) in a ratio of about 10:90, 15:85, 20:80, 25:75, 30:70,35:65, 40:60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20,85:15, 90:10, 95:5, 99:1 and initiating the polymerization of themonomers to provide a copolymer.

In some embodiments, the ratio of monomers and the initiator, orinitiator system, can be selected as described above. The method mayinclude further components to provide a copolymer with desirableproperties. For example, the method may include a surfactant, such as,for example, Aerosol® OT, or a crosslinker, such as, for example,1,6-hexanediol dimethacrylate.

Polymerization can occur in an aqueous mixture or a mixture thatcomprises both aqueous and organic solvents. For example, thepolymerization mixture can include a mixture of water and acetone. Insome embodiments the polymerization mixture may require an organicsolvent. Often it will be desirable to include an organic solvent whenlauryl methacrylate is in the polymerization mixture. Organic solventsfor use in such polymerization reactions are known and routinelyselectable by those of ordinary skill in the field of polymer synthesis.Suitable organic solvents include, for example and without limitation,acetone, 2-butanone, methanol, ethanol, and isopropanol.

The copolymer of the first or second aspect can be present in the oil inan amount from about 0.5% to about 25% by weight. Depending on the oilused the, the copolymer may be present in the oil in an amount fromabout 1% to about 25.

The oil may be selected from those known in the art, and may be amineral oil, i.e., those obtained from the processing of crude oil, or asynthetic oil, i.e., an artificially made oil typically containingpolyglycols or esters, or a semi-synthetic oil, i.e., a blend of mineraland synthetic oils. In some embodiments, the oil is a mineral base oil,i.e., a complex mixture of paraffins, naphthenes, and aromatics. In someexamples, the oil may be a paraffinic base oil, such as 150 NeutralSolvent, 600 Solvent Neutral or a bright stock. The oil composition mayinclude further components, particularly those used in marine dieselengine oil lubricants.

A test measuring the enhanced lubrication properties and usability ofoil containing a copolymer of the first or second aspect was undertakenunder the following conditions. The oil/polymer compositions wereexamined for performance/suitability as a lubricant by a finger pulltest, which is performed by pipetting a droplet of sample fluid (about65 μl) onto the thumb of a gloved hand. The thumb and forefinger aregently squeezed together to ensure contact of the droplet with bothfingers, and then the fingers are pulled apart vertically for about 1second over a distance of about 7.5 cm., while observing the amount oftime the composition provides a fluid connection between the thumb andforefinger once the fingers are moved apart. All finger pull tests wereperformed at ambient temperature, about 21° C. The performance of thesample was characterized as “very short,” “short,” “medium,” “long,” or“very long” depending upon the duration that the sample provided a fluidconnection between thumb and forefinger remain. Compositions with “veryshort” performance in the finger pull test being less than 1 second,“short” ranging from 1-4 seconds, “medium” ranging from 4-7 seconds,“long” ranging from 7-60 seconds, and “very long” describing thesituation where the composition remains connected to both fingersindefinitely. Compositions with “very short” and “very long” textures donot exhibit enhanced suitability or performance as a lubricant.Compositions with “short,” “medium,” or “long” textures exhibit improvedsuitability as a lubricant to varying degrees because, for example,their ability to effectively spread on the cylinder wall of the enginebeing lubricated is enhanced. Compositions with “long” texture haveparticularly good suitability as a lubricant. The results of the fingerpull test are shown in Table 2.

One advantage of the copolymers disclosed herein is that they can beused to enhance the performance of an oil as a lubricant, while at thesame time maintaining the ability to handle the oil in a mannernecessary for use in the field. For example, many lubricants are pumpedvia a fluid pump, and therefore the lubricant should have an appropriateviscosity to allow it to be pumped without creating mechanicalcomplications or damage to the pumping equipment. A lubricant withimproper viscosity (particularly a viscosity that is too high) canprevent the lubricant from being pumped properly, or otherwise requirethe exertion of much higher power to pump the lubricant. The polymersdisclosed herein maintain the balance between enhancing lubricant oilperformance while at the same time maintaining the viscosity at asufficient level to allow for efficient handling in the field. It hasbeen unexpectedly discovered that the combination of Monomer Bhomopolymer with oil also provides enhanced lubricant performance at aviscosity that allows for efficient handling. The combination of oilwith a copolymer having a 5:95 Monomer B to Monomer A ratio results in asubstance having a viscosity and other physical handling properties thatprevent this composition from being efficiently handled in the field.

In an embodiment the polymers have a molecular weight >20000 D.

In an embodiment the polymers have a bimodal molecular weightdistribution.

Copolymers having a molecular weight (Mw), average root mean squareradius of gyration (Rg) and viscosity correlation in a certain range areparticularly suitable as an oil additive to enhance the performance ofoil as a lubricant while maintaining the ability to handle and pump theoil. A preferred correlation of a bimodal Mw, Rg and viscosity valuesfor one embodiment of the copolymers disclosed herein is represented bythe following formula:

Performance X=1139.69418+(2.54756*Peak 1 Mw)−(0.91396*Peak 1Rg)−(66.18535*Peak 2 Mw)−(0.23020*Viscosity+1.18947E-003*Peak 1Rg)*(Viscosity),

where the units for Mw is 10⁶ g/mol, Rg is nm, and Viscosity is mPa·s,as set forth in Table 2. A performance X value between 500 and 900, morepreferably between 550 and 800, and most preferably between 600 and 750is indicative of a copolymer having properties that are particularlysuitable to enhance the performance of oil as a lubricant.

Definitions

As used herein, lauryl methacrylate is dodecyl methacrylate (C₁₂; CAS142-90-5) or a mixture of C₁₄₋₁₆alkyl methacrylates including dodecylmethacrylate. That is, lauryl methacrylate may include a mixture ofwhich dodecyl methacrylate is a component, but which also includes oneor more other C₁₄₋₁₆alkyl methacrylates such as tetradecyl methacrylate(C₁₄; CAS 2549-53-3) and hexdecyl methacrylate (C₁₆; CAS 2495-27-4). Forexample, the lauryl methacrylate could be a mixture of about 40-70weight percent dodecyl methacrylate, 15-40 weight percent tetradecylmethacrylate, and 4-10 weight percent hexdecyl methacrylate, such ascommercially available methacrylic ester 13.0 (Evonik trade name:VISIOMER® Terra C13,0-MA).

As used herein, the term “about” refers to the given value±10% of thevalue.

As used herein, the term “C₈alkyl” refers to a group comprised of eightsaturated carbon atoms connected in a linear or branched configuration.Examples of linear C₈alkyl groups include n-octyl. Examples of branchedC₈alkyl groups include, but are not limited, to 2-ethylhexyl.

As used herein, the term “alkyl methacrylate” refers to compoundswherein a methacrylol radical is bonded to a linear or branched,saturated or unsaturated alkyl group.

As used herein, the term “substantially free of monomers” means thatthere is no more than 3.0% by weight of the copolymer, preferably nomore than 1.0% by weight, and more preferably no more than 0.5% byweight of the monomer present in the copolymer.

As used herein, the term “substantially free of crosslinking agents”means that there is no more than 1.0% by weight of the copolymer,preferably no more than 0.5% by weight, of monomeric units that connecttwo or more of the backbone chains of the polymer.

It is noted that any embodiment disclosed herein can be combined withany other embodiment with the result being subject matter in accordancewith the invention.

It is noted that, unless use differently, “%” means percent by weight.

EXAMPLES

Lauryl methacrylate as used in Examples 1-8 was provided as methacrylicester 13.0, which is commercially available as VISIOMER Terra C13,0-MAfrom Evonik Industries.

Example 1

To a 4-neck 2000 mL flask equipped with an overhead stirrer, acondenser, a thermocouple and a subsurface nitrogen purge was added645.5 g of water and 8.7 g of Aerosol® OT. The stirring was turned up to200 rpm and the subsurface nitrogen purge was started. To the reactionwas then added container 270.0 g of lauryl methacrylate, 30.0 g of2-ethylhexyl methacrylate and 129.9 g of acetone. The reaction washeated up to 43° C. by using a temperature controlled water batch set at45° C. Once the reaction reached 43° C., 0.04 g of t-butyl hydroperoxidein 7.5 g of water was added. After 5 minutes, 0.29 g of sodium ascorbatedissolved in 7.5 g of water and 0.60 g of a 0.25% solution of ironsulfate hexahydrate was added. The nitrogen purge was then changed to anitrogen blanket. The reaction was held an additional 5 hours, cooled toroom temperature and isolated.

Example 2

To a 4-neck 2000 mL flask equipped with an overhead stirrer, acondenser, a thermocouple and a subsurface nitrogen purge was added645.5 g of water and 8.7 g of Aerosol® OT. The stirring was turned up to200 rpm and the subsurface nitrogen purge was started. To the reactionwas then added container 240.0 g of lauryl methacrylate, 60.0 g of2-ethylhexyl methacrylate and 129.9 g of acetone. The reaction washeated up to 43° C. by using a temperature controlled water batch set at45° C. Once the reaction reached 43° C., 0.04 g of t-butyl hydroperoxidein 7.5 g of water was added. After 5 minutes, 0.29 g of sodium ascorbatedissolved in 7.5 g of water and 0.60 g of a 0.25% solution of ironsulfate hexahydrate was added. The nitrogen purge was then changed to anitrogen blanket. The reaction was held an additional 5 hours, cooled toroom temperature and isolated.

Example 3

To a 4-neck 2000 mL flask equipped with an overhead stirrer, acondenser, a thermocouple and a subsurface nitrogen purge was added645.5 g of water and 8.7 g of Aerosol® OT. The stirring was turned up to200 rpm and the subsurface nitrogen purge was started. To the reactionwas then added container 210.0 g of lauryl methacrylate, 90.0 g of2-ethylhexyl methacrylate and 129.9 g of acetone. The reaction washeated up to 43° C. by using a temperature controlled water batch set at45° C. Once the reaction reached 43° C., 0.04 g of t-butyl hydroperoxidein 7.5 g of water was added. After 5 minutes, 0.29 g of sodium ascorbatedissolved in 7.5 g of water and 0.60 g of a 0.25% solution of ironsulfate hexahydrate was added. The nitrogen purge was then changed to anitrogen blanket. The reaction was held an additional 5 hours, cooled toroom temperature and isolated.

Example 4

To a 4-neck 2000 mL flask equipped with an overhead stirrer, acondenser, a thermocouple and a subsurface nitrogen purge was added645.5 g of water and 8.7 g of Aerosol® OT. The stirring was turned up to200 rpm and the subsurface nitrogen purge was started. To the reactionwas then added container 180.0 g of lauryl methacrylate, 120.0 g of2-Ethylhexyl Methacrylate and 129.9 g of acetone. The reaction washeated up to 43° C. by using a temperature controlled water batch set at45° C. Once the reaction reached 43° C., 0.04 g of t-butyl hydroperoxidein 7.5 g of water was added. After 5 minutes, 0.29 g of sodium ascorbatedissolved in 7.5 g of water and 0.60 g of a 0.25% solution of ironsulfate hexahydrate was added. The nitrogen purge was then changed to anitrogen blanket. The reaction was held an additional 5 hours, cooled toroom temperature and isolated.

Example 5

To a 4-neck 2000 mL flask equipped with an overhead stirrer, acondenser, a thermocouple and a subsurface nitrogen purge was added645.5 g of water and 8.7 g of Aerosol® OT. The stirring was turned up to200 rpm and the subsurface nitrogen purge was started. To the reactionwas then added container 120.0 g of lauryl methacrylate, 180.0 g of2-Ethylhexyl Methacrylate and 129.9 g of acetone. The reaction washeated up to 43° C. by using a temperature controlled water batch set at45° C. Once the reaction reached 43° C., 0.04 g of t-butyl hydroperoxidein 7.5 g of water was added. After 5 minutes, 0.29 g of sodium ascorbatedissolved in 7.5 g of water and 0.60 g of a 0.25% solution of ironsulfate hexahydrate was added. The nitrogen purge was then changed to anitrogen blanket. The reaction was held an additional 5 hours, cooled toroom temperature and isolated.

Example 6

To a 4-neck 2000 mL flask equipped with an overhead stirrer, acondenser, a thermocouple and a subsurface nitrogen purge was added645.5 g of water and 8.7 g of Aerosol® OT. The stirring was turned up to200 rpm and the subsurface nitrogen purge was started. To the reactionwas then added container 60.0 g of lauryl methacrylate, 240.0 g of2-Ethylhexyl Methacrylate and 129.9 g of acetone. The reaction washeated up to 43° C. by using a temperature controlled water batch set at45° C. Once the reaction reached 43° C., 0.04 g of t-butyl hydroperoxidein 7.5 g of water was added. After 5 minutes, 0.29 g of sodium ascorbatedissolved in 7.5 g of water and 0.60 g of a 0.25% solution of ironsulfate hexahydrate was added. The nitrogen purge was then changed to anitrogen blanket. The reaction was held an additional 5 hours, cooled toroom temperature and isolated.

Example 7

To a 4-neck 2000 mL flask equipped with an overhead stirrer, acondenser, a thermocouple and a subsurface nitrogen purge was added645.5 g of water and 8.7 g of Aerosol® OT. The stirring was turned up to200 rpm and the subsurface nitrogen purge was started. To the reactionwas then added 30.0 g of lauryl methacrylate, 270.0 g of 2-EthylhexylMethacrylate and 129.9 g of acetone. The reaction was heated up to 43°C. by using a temperature controlled water batch set at 45° C. Once thereaction reached 43° C., 0.04 g of t-butyl hydroperoxide in 7.5 g ofwater was added. After 5 minutes, 0.29 g of sodium ascorbate dissolvedin 7.5 g of water and 0.60 g of a 0.25% solution of iron sulfatehexahydrate was added. The nitrogen purge was then changed to a nitrogenblanket. The reaction was held an additional 5 hours, cooled to roomtemperature and isolated.

Example 8

To a 4-neck 2000 mL flask equipped with an overhead stirrer, acondenser, a thermocouple and a subsurface nitrogen purge was added645.5 g of water and 8.7 g of Aerosol® OT. The stirring was turned up to200 rpm and the subsurface nitrogen purge was started. To the reactionwas then added 15.0 g of lauryl methacrylate, 285.0 g of 2-EthylhexylMethacrylate and 129.9 g of acetone. The reaction was heated up to 43°C. by using a temperature controlled water batch set at 45° C. Once thereaction reached 43° C., 0.04 g of t-butyl hydroperoxide in 7.5 g ofwater was added. After 5 minutes, 0.29 g of sodium ascorbate dissolvedin 7.5 g of water and 0.60 g of a 0.25% solution of iron sulfatehexahydrate was added. The nitrogen purge was then changed to a nitrogenblanket. The reaction was held an additional 5 hours, cooled to roomtemperature and isolated.

Preparation of 5% Solids Solution of Copolymer in Oil

To a 4-neck 1000 mL flask equipped with an overhead stirrer, a Barrettdistillation trap with a condenser and a thermocouple was added anamount of the emulsion of any of Examples 1-8 to give 20.0 g of polymer.Neutral Solvent 600 was then added to bring the total up to 400.0 g,followed by 150.0 g of toluene. The stirring was turned up to 200 rpmand the mixture was brought up to reflux. As water condensed in theBarrett trap it was drained off. Once the water stopped overflowing, thecontents of the reactor were brought up to 130° C. to distill of amajority of the toluene. The remaining material was transferred to a1000 mL single neck round bottom and concentrated at vacuum with a bathat 60° C. until the material reached a constant weight.

Method for Determining Molecular Weight and Radius of Gyration

The Molecular Weight and Radius of Gyration of the polymer samples,supplied at 5% solids in base oil, was determined by the procedureoutlined below:

Eluant: HPLC Grade Tetrahydrofuran stabilized with 0.01% ButylatedHydroxytoluene

Column: Phenogel Column 100A 10 um 300 mm×7.8 mm.

Flow Rate: 0.50 ml/min.

Detectors: Wyatt Dawn Heleos-II MultiAngle Light Scattering (MALS) at663 nm and room temperature and Wyatt Optilab T-rEX Refractive IndexDetector at 658 nm and 40° C.

Pump/Autosampler: Agilent 1100 Isocratic HPLC Pump and Autosampler

Column Compartment: 40° C.

Standards: There were no standards directly correlated with theanalysis, but the Heleos-II MALS calibration constant was establishedwith Toluene and the Optilab T-rEX calibration constant was establishedwith NaCl in water. The 17 angles on the Heleos-II were normalized witha narrow range polystyrene standard at 28,500 Molecular Weight and thedetector delay volume was adjusted with the same standard.

Sample Preparation: The samples were prepared by gravimetricallydiluting about 8.0 mg of sample with about 5.0 g of tetrahyrofuran. Theactual concentration of polymer in mg/ml was calculated based on thedensity of tetrahydrofuran (0.889 g/ml) and the percentage solids in thesample solutions (5.0% by weight).

Injection: 50 μl.

Run time: 20 minutes.

Software: Wyatt Astra Version 6.1.4.25.

Calculations: The Astra software provides several choices of formalismsand exponent order to fit the data. All samples were fit with a 2^(nd)order Berry. The angles used were adjusted to give the best fit, using aminimum of 13 angles and up to the maximum of 17. The dn/dc wascalculated from the refractive index data assuming 100% recovery. Thesoftware reported the average Molecular Weight as Mw and the averageRoot Mean Square Radius of Gyration as Rg. The results are shown inTable 2.

Method for Determining Viscosity

The shear viscosity of the polymer samples, supplied at 5% solids inbase oil, was determined by stress-controlled rheometer MCR 302,manufactured by Anton Paar GmbH, located at Anton Paar Strasse 20, 8054,Graz, Austria. The Double Gap System of Measurement was used for goodaccuracy (Instruction Manual, MCR Series, Modular Compact Rheometer MCR52/102/302/502, page 50, Anton Parr, Graz, Austria, 2011). Thetemperature was set at 22° C. with the accuracy of 0.1° C. The shearrate was gradually increased from 1/sec to 100/sec with 10 points ofviscosity reading per decade. At each of these points, 10 secondequilibrium time was given before the reading, which lasted 3 seconds.The viscosity at 10/sec shear rate is shown in Table 2. Software forinstrument control and data acquisition is RheoCompass™, version1.13.445.

TABLE 1 2- FeSO4² Aerosol Example LMA¹ EHMA¹ Acetone² TBHP² Ascorbate²(0.25%) OT² 1 90 10 43.3 0.013 0.098 0.20 2.90 2 80 20 43.3 0.013 0.0980.20 2.90 3 70 30 43.3 0.013 0.098 0.20 2.90 4 60 40 43.3 0.013 0.0980.20 2.90 5 40 60 43.3 0.013 0.098 0.20 2.90 6 20 80 43.3 0.013 0.0980.20 2.90 7 10 90 43.3 0.013 0.098 0.20 2.90 8  5 95 43.3 0.013 0.0980.20 2.90 NS600 — — — — — — — Base Oil ¹Percentage of monomer as a masspercent of the total amount of monomer ²Weight percent based on thetotal amount of monomer LMA = lauryl methacrylate; 2-EHMA = 2-ethylhexylmethacrylate.

TABLE 2 Hydrodynamic Chromatography/MALS 5% S Mw Rg Rg NS600 Finger 2-Mw Peak 1 Peak 2 Peak 1 Peak 2 viscosity Pull Example LMA¹ EHMA¹(10^(6 g/mol)) (10^(6 g/mol)) (nm) (nm) [mPa · s] Test² 1 90 10 133 6.4140 108 3610 l 2 80 20 133 7.0 135 104 2152 l 3 70 30 146 7.0 132 1062572 m 4 60 40 169 9.7 135 119 2294 m 5 40 60 129 8.1 133 111 4865 l 620 80 132/131 8.1/7.6 152/152 122/120 4089 l 7A³ 10 90  92 5.3 166 1018213 l 7B 10 90 136/149 6.4/7.2 176/176 112/118 10600 l 8  5 95  36 5.4192 112 41083 vl NS600 — — — — — — 300 vs Base Oil ¹Percentage ofmonomer as a mass percent of the total amount of monomer LMA = laurylmethacrylate; 2-EHMA = 2-ethylhexyl methacrylate; ²vs = very short, s =short, m = medium, l = long, vl = very long ³Two duplicate samples forExample 7 were created using the Example 7 preparation method described

1. An uncrosslinked copolymer of alkyl methacrylate monomers whereinsaid alkyl methacrylate monomers comprise: a. Monomers (A) selected fromC6-C10 alkyl methacrylate monomers, and b. Monomers (B) selected fromC10-C18 alkyl methacrylate monomers, wherein the mass ratio of Monomers(B) in the copolymer to Monomers (A) in the copolymer is 99:1 to 60:40by weight, wherein Monomers (A) and Monomers (B) are distinct from oneanother, wherein the copolymer contains not more than 3.0% by weight,preferably not more than 1.0% by weight, more preferably not more than0.5% by weight of methyl methacrylate, and wherein the copolymer has anaverage root mean square radius of gyration from 100 nm to 200 nm asmeasured by hydrodynamic column chromatography-multi angle lightscattering where tetrahydrofuran is used as a solvent.
 2. Anuncrosslinked copolymer obtained by combining at least: a. Monomers (A)selected from C6-C10 alkyl methacrylate monomers, and b. Monomers (B)selected from C10-C18 alkyl methacrylate monomers, in a mixture andco-polymerizing the monomers, wherein the monomers are present in a massratio of 99:1 to 60:40 Monomers (B) to Monomers (A), wherein Monomers(A) and Monomers (B) are distinct from one another, wherein thecopolymer contains not more than 3.0% by weight, preferably not morethan 1.0% by weight, more preferably not more than 0.5% by weight ofmethyl methacrylate, and wherein the copolymer has an average root meansquare radius of gyration from 100 nm to 200 nm as measured byhydrodynamic column chromatography-multi angle light scattering wheretetrahydrofuran is used as a solvent.
 3. The copolymer of claim 1wherein the mass ratio of the monomers is about 80:20 Monomers (B) toMonomers (A).
 4. The copolymer of claim 1 wherein the mass ratio of themonomers is about 90:10 Monomers (B) to Monomers (A).
 5. The copolymerof claim 1 wherein Monomers (B) are lauryl methacrylate.
 6. Thecopolymer of claim 1 wherein Monomers (A) are C₈alkyl methacrylate. 7.The copolymer of claim 6 wherein the C₈alkyl methacrylate is 2-ethylhexyl methacrylate.
 8. The copolymer of claim 1 wherein the copolymer isa substantially random copolymer.
 9. The copolymer of claim 1 whereinthe copolymer is a partially random copolymer and partially a blockcopolymer.
 10. The copolymer of claim 1 wherein monomers (A) andmonomers (B) represent at least 75% by weight of the total weight ofmonomers used to prepare the copolymer, preferably at least 90%, morepreferably at least 95%, or more preferably 99% by weight.
 11. Thecopolymer of claim 1 wherein the copolymer is a mixture of C12 alkylmethacrylate, C14 alkyl methacrylate, C16 alkyl methacrylate, and C18alkyl methacrylate, and a C8 alkyl methacrylate.
 12. An uncrosslinkedcopolymer of C₈ alkyl methacrylate and lauryl methacrylate, wherein themass ratio of lauryl methacrylate monomers in the copolymer to C₈ alkylmethacrylate monomers in the copolymer is 99:1 to 60:40 by weight, andwherein the copolymer has an average root mean square radius of gyrationfrom 100 nm to 200 nm as measured by hydrodynamic columnchromatography-multi angle light scattering where tetrahydrofuran isused as a solvent.
 13. (canceled)